1. Field of the Invention
This invention relates to wheeled irrigation systems having multiple wheeled frames and more particularly, to a hydraulic lifting device for mounting on the three-point attachment system of a vehicle such as a tractor and deployment in the field for raising the axles of the wheeled frames and pivoting the wheels in a transverse or longitudinal configuration with respect to the axles, respectively. In a preferred embodiment the hydraulic lifting device includes a tractor-mounted, vertically-oriented support frame which slidably supports a carriage fitted with upper and lower lifting member sleeves for removable receiving a lifting member designed to engage the respective axles of the irrigation system frame for lifting purposes. A hydraulic cylinder is mounted in the support frame with the piston attached to the carriage and the cylinder operates the carriage with respect to the frame for raising and lowering the lifting member and hence, the respective irrigation frame axles and wheels. The support frame may be quickly and easily attached to the three-point hook-up on a tractor and moved into the field for quick and easy engagement with the respective axles of the irrigation frame to effect sequential lifting and facilitate pivoting of the wheels with a minimum of effort in a short time.
2. Description of the Prior Art
Various types of hydraulic lift mechanisms are well known in the art. A "Hydraulic Lift Truck" is detailed in U.S. Pat. No. 2,163,675, dated Jun. 27, 1939, to P. D. Germond. The lift truck is fitted with a hydraulic cylinder and wheels for rolling beneath a vehicle and lifting the vehicle to a desired height. A "Tractor Jack" is detailed in U.S. Pat. No. 2,250,964, dated Jul. 29, 1941, to T. W. Poor, et al. The tractor jack includes a jack frame adapted for mounting on the frame of the tractor at the front and rear wheel areas for simultaneously jacking both the front and rear wheels by manipulation of the three-point attachment of the tractor. U.S. Pat. No. 2,375,970, dated May 15, 1945, to W. W. Williams, Jr., details a "Hydraulic Drawbar Lift for Tractors". The hydraulic drawbar includes a pivot drawbar that is raised or lowered by means of a hydraulic ram mechanism connected by a system of levers to the drawbar. The pump of the ram mechanism is operated by an electric motor carried by the casing of the mechanism and the motor is energized by current from the standard storage battery of the electrical system in the tractor. Another "Tractor Jack" is detailed in U.S. Pat. No. 2,712,431, dated Jul. 5, 1955, to G. W. Findley. The tractor jack includes a jack frame attached to the three-point attachment of the tractor and arranged such that either the front or rear end of the tractor can be selectively elevated by operation of the three-point hydraulic attachment. U.S. Pat. No. 3,549,125, dated Dec. 22, 1970, to David Hamilton, details an "Extension Frame for Hydraulic Jacks". The extension frame is suitable for lifting trailers and includes an elongated housing containing a telescopically extensible tube. The tube includes a supporting leg in one end and a base at the other end, to the latter of which the jack is secured by bolts. A stationary rod is mounted in the housing and serves as a guide for a coiled spring surrounding the stationary rod. The coiled spring is compressed when the jack is actuated and urges the extensible tube into the housing when jacking pressure is released.
It is an object of this invention to provide a lifting device which is capable of being removably attached to a vehicle such as a pickup truck or a tractor and moved into the field for various lifting purposes, such as raising the respective axles and wheels of a wheeled irrigation system to facilitate pivoting of the wheels into a longitudinal or transverse configuration with respect to the axles.
Another object of the invention is to provide a hydraulic lifting device which is designed for attachment to the conventional three-point hook-up on a tractor for transportation to the field and is fitted with a removable lifting member for engaging the respective axles of a wheeled irrigation support frame and raising the axles and wheels to facilitate elevation and pivoting of the respective wheels into a longitudinal or transverse configuration with respect to the axles.
Yet another object of this invention is to provide a cylinder-operated lifting device which is characterized by an upward-standing support frame, a carriage vertically and slidably mounted in the support frame, a fluid-operated cylinder connected to the support frame and carriage and at least one set of lifting member sleeves adapted for removably receiving a lifting member designed to engage the respective axles of a wheeled irrigation support frame and raise the axles and connected wheels to facilitate pivoting of the wheels into a transverse or longitudinal configuration with respect to the axles.
A still further object of this invention is to provide a hydraulic lifting device for mounting on the three-point attachment of a tractor, which hydraulic lifting device is characterized by a vertical support frame, a carriage slidably mounted in vertical relationship on the support frame and fitted with upper and lower lifting member sleeves for receving a removable lifting member and a hydraulic cylinder mounted on the support frame with the cylinder piston connected to the carriage, for raising and lowering the carriage and the lifting member to, in turn, raise and lower the respective axles of a wheeled irrigation support and facilitate selective rotation of the wheels attached to the axles into a transverse or longitudinal configuration with respect to the axles.